!(function(n) {
  const e = n.document
  const t = e.documentElement
  const i = 750 // 375分辨率
  const d = i / 200
  const o = 'orientationchange' in n ? 'orientationchange' : 'resize'
  const a = function() {
    let n = t.clientWidth || 320
    n > i && (n = i)
    t.style.fontSize = `${n / d}px`
  }
  e.addEventListener &&
    (n.addEventListener(o, a, !1),
    e.addEventListener('DOMContentLoaded', a, !1))
}(window))
// 1：100   rem
